Officials at Howard University Hospital said doctors began the surgery Friday afternoon.

A spokeswoman for Barry said the kidney donor is a longtime friend of the District of Columbia Council member.

Barry, 72, served four terms as mayor. In his third, he was videotaped in 1990 in a hotel room smoking crack cocaine in an FBI sting. He served six months in prison and in 1994 regained the mayor's office and later became a councilman.

Now he's facing fresh legal woes. Prosecutors are seeking to have Barry jailed for failing to file his 2007 federal and local tax returns — saying that was the eighth time in nine years that Barry failed to file returns.

He was given three years of probation in 2006 after pleading guilty to misdemeanor charges for failing to file his tax returns from 1999 to 2004. The latest episode was revealed when federal prosecutors asked a judge last week to revoke Barry's probation for failing to file his 2007 tax returns.

The kidney problems are the result of diabetes and hypertension that Barry has suffered for more than 20 years, his spokeswoman Natalie Williams said.